You should find that cable allows more bandwidth, period. In most cases you'll get a better ping to the same server on cable rather than DSL, and file transfers with cable are through the roof.
Usually with DSL I get pings of 40-70 to Aus based game servers, compared to most cablers getting 30, really not that noticable.
Incomming on 512/128 is around 60 kbps, compared to cablers who can manage 500 kbps ...
If you can get cable, get it. If you can't, settle for DSL. Both great broadband services.